The production of semiconductor substrates, wafers and photomasks has traditionally used processing equipment in which various types of processing fluids are used. One example of a semiconductor processor is a centrifugal rinser-dryer which uses water and dilute cleaning solutions. Other processors use acids, caustics, etchants, solvents and other processing fluids which are applied to the substrates, wafers, photomasks, data disks, flat panel displays and other semiconductor-related units.
A constant challenge in the production of semiconductors is particle contamination. With respect to all types of semiconductor processors, preventing contaminant particles from entering into the processor enclosure is of paramount importance. Such particles can affect the photographic processes used to transfer the chip layouts onto the wafers being processed into chips, and can further cause deterioration of the image being transferred onto the wafer. Even more susceptible to contamination is the direct processing of the wafers because of the numerous processing steps that take place. With each step there is a risk that contaminating particles may adhere to the surface of the wafer. Once contaminant particles are transferred onto the surface of the wafer, they are often difficult to remove.
One of the greatest sources of contaminating particles is the presence of environmental dust carried in the air surrounding the semiconductor processors. To reduce the amount of environmental contamination, manufacturers have taken extreme measures to provide working areas with relatively low amounts of environmental dust. These areas are called "clean rooms". Such working areas are expensive to build and operate. Hence, there is a substantial need to provide semiconductor processing equipment that minimizes the risk of contamination.
Another problem associated with traditional semiconductor processors relates to toxic and corrosive processing fluids, such as acids, caustics, solvents and other processing fluids. Such processing fluids must be maintained within the processing chamber to avoid corrosion and other harmful effects to personnel and materials outside of the semiconductor processor enclosure. Of concern are both liquid and gaseous forms of processing fluids, both of which should be prevented from exiting the processor enclosure and contacting machine parts susceptible to corrosion.
Processing fluids are preferably contained within the enclosure both during processing and when access into the processing chamber is needed. A common problem arises with respect to leakage of processing fluids around the area where the processor door seals against the processor bowl or other processing enclosure. For example, processing within a centrifugal processor having a horizontal or inclined axis of rotation and upstanding front access opening will result in liquids collecting along the walls of the access opening port. These collected liquids tend to run down along the walls and can collect near the bottom of the opening part. When the door is opened the collected liquids drip, flow or otherwise escape outwardly from the access opening to the exterior of the processing enclosure and down along the front panel of the processor. These fluids may even reach the floor around the processing enclosure. This leakage also creates undesirable working conditions. In addition, corrosive processing fluids may cause injury or damage to the equipment or building. Thus, there exists a need to provide semiconductor processing equipment having an improved door construction which prevents processing fluids from escaping and causing undesirable effects.
Various attempts have been made to provide doors for semiconductor processing equipment that will adequately seat the access opening to prevent contaminant particles from entering and prevent processing fluids and vapors from escaping. However, because of the need to precisely align the door with the enclosure access opening, traditional equipment has required substantial in-field adjustments to ensure that the door seals properly within the access opening. Maintaining adjustment of such doors has involved excessive amounts of time and labor. Furthermore, because of the many mechanical working parts required for the adjustments, the risk of mechanical failure of the doors has been high.
There remains a substantial need for semiconductor processing equipment which is easy to install and service in the field and minimally susceptible to mechanical failure. There is also a substantial need to provide semiconductor processing equipment that minimizes leakage of processing fluids and prevents contaminating particles from passing to the interior of the processing chamber. The present invention provides substantial and surprising benefits with respect to these needs.